The panorama of cerebral palsy in Sweden. XI. Changing patterns in the birth-year period 2003-2006.

Aim: To describe the epidemiology of cerebral palsy (CP) in western Sweden.

Methods: A population-based study covering 94 466 live births in the area in 2003-2006. Birth characteristics and neuroimaging findings were recorded, prevalence was calculated and aetiology was analysed.

Results: CP was found in 206 children, including postneonatal cases, corresponding to a crude prevalence of 2.18 per 1000 live births. The gestational age-specific prevalence for <28 gestational weeks was 71.4 per 1000 live births, while it was 39.6 for 28-31 weeks, 6.4 for 32-36 weeks and 1.41 per 1000 for >36 weeks. Hemiplegia accounted for 44%, diplegia for 29% and tetraplegia for 6%, while 16% had dyskinetic CP and 5% had ataxia. Neuroimaging was available in 95% of the children. This showed maldevelopment in 13%, white matter lesions in 36%, cortical/subcortical lesions in 23% and basal ganglia lesions in 14%. The aetiology was considered to be prenatal in 36% and perinatal/neonatal in 46% and remained unclassified in 18%.

Conclusion: The overall prevalence of CP in western Sweden was stable. However, the distribution of CP types changed and the term hemiplegia increased significantly. Among children with CP born extremely preterm, the percentage born before 26 weeks of gestation had increased.